For many years harvesters, such as agricultural balers, have been used to consolidate and package crop material so as to facilitate the storage and handling of the crop material for later use. Usually, a mower-conditioner cuts and conditions the crop material for windrow drying in the sun. When the cut crop material is properly dried, a harvester, such as a round baler, the most frequently used in the industry, travels along the windrows to pick up the crop material and form it into cylindrically-shaped round bales.
More specifically, the cut crop material is gathered at the front of the baler from along the ground, onto a pickup assembly, and into a crop feeding channel where the material can be further cut before being introduced into a bale-forming chamber. Traditionally, the crop feeding channel is more narrow than the surrounding areas of the harvester, and clogging or plugging of the crop feeding channel is a common problem, especially if the harvester is being operated at higher speeds and thus passing greater amounts of crop material through the crop feeding channel at a given time. Once a clog occurs, the harvester must be stopped for the crop feeding channel to be cleared, reducing harvesting efficiency.
One method to prevent clogging is to design a harvester with a limited amount of movement of the bottom floor of the crop feeding channel. The bottom floor physically supports the crop material as it passes through the crop feeding channel and is cut by a rotor and knives before being moved to the bale forming chamber. By allowing the bottom floor to move, it can temporarily increase the volume of crop material that can be passed through the crop feeding channel, possibly preventing the formation of a clog. Once such example is described in U.S. Pat. No. 5,819,517, where the bottom floor of a crop feeding channel is allowed limited movement at the front end of the bottom floor, where the crop material would enter the crop feeding channel. This limited movement is accomplished by a spring that provides tension between the frame of the harvester and the front end of the bottom floor. If the pressure of the crop material in the crop feeding channel is great enough, the front end of the bottom floor will move downward, allowing additional crop material to pass through the channel. One disadvantage of this system is that the rear of the bottom floor remains static, so that while the volume of the crop feeding channel will increase towards the front, this larger amount of crop material must still pass through a fixed volume rearward to the rotary cutter. This frontside movement greatly increases the likelihood of clogs at a narrow outlet of the crop feeding channel and does not address the fundamental problem of accommodating more crop through the passageway defined by a drop floor. Additionally, in this arrangement the crop cutting knives remain static, and cannot compensate for increased crop material volume.
Another example is described in U.S. Pat. No. 7,584,594, in which both the front and the rear of the bottom floor of a feeding assembly provide limited movement. Movement at the front of the bottom floor is accomplished by a slotted guide and the rear by a hydraulic cylinder, such that when the rear of the bottom floor moves downward, so too will the front of the bottom floor. One disadvantage of this system is that the bottom floor is allowed a great deal of movement from its initial position, potentially allowing large variations in crop material volume to enter in the bale forming chamber. Large variations in crop material can cause uneven bale formation and improper or incomplete cutting of crop material.
The instant application addresses these deficiencies by providing a crop collection system that allows a one-sided, limited movement of a bottom floor of a crop feeding channel that both prevents clogging of the feed channel due to occasional high crop material volume, and still provides for proper bale formation.